A remote nonconjugated electron effect in insertion polymerization with α-diimine nickel and palladium species
Systematic investigations of ligand electronic effects in late transition metal catalyzed ethylene polymerization and copolymerization have been widely explored in different catalytic systems. Generally, the electronic effect regulation in olefin polymerization can be achieved by replacing substitue...
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Published in | Polymer chemistry Vol. 11; no. 15; pp. 2692 - 2699 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
Cambridge
Royal Society of Chemistry
21.04.2020
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Subjects | |
Online Access | Get full text |
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Summary: | Systematic investigations of ligand electronic effects in late transition metal catalyzed ethylene polymerization and copolymerization have been widely explored in different catalytic systems. Generally, the electronic effect regulation in olefin polymerization can be achieved by replacing substituents with different electronic effects through the conjugate effect to influence the catalytic metal center. In this contribution, we describe the synthesis and characterization of a series of bulky α-diimine ligands and the corresponding nickel and palladium catalysts bearing a diarylmethyl moiety with different electronic effects. The bulky nickel complexes show great thermal stability, and achieve the highest activity at 80 °C in ethylene polymerization. The generated polyethylene possesses very high molecular weight, moderate branching density and moderate melting temperature even at 80 °C. The corresponding palladium complexes display moderate activity and generate high molecular weight semicrystalline polyethylene with low branching density. The high molecular weight polar functionalized polyethylene can also be obtained using these palladium complexes. Surprisingly, the remote nonconjugated electronic perturbations exert great influence on the ethylene polymerization in terms of the polymerization activities and polymer microstructures.
The remote nonconjugated electronic perturbations exert great influence on ethylene polymerization. |
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Bibliography: | CCDC Electronic supplementary information (ESI) available: Full experimental details for the synthesis of nickel and palladium complexes and polymers, and CIF files for complexes Pd4 For ESI and crystallographic data in CIF or other electronic format see DOI and 1979308 1979307 of Pd3-Pd4 10.1039/d0py00218f Pd3 |
ISSN: | 1759-9954 1759-9962 |
DOI: | 10.1039/d0py00218f |